A state department of education, as a question on the public-release form of a statewide standardized test, released a question to the public in which third-grade students have to solve a word problem using subtraction.
This question tells us that two students were collecting rocks for a science project. One of the students was able to collect 489 rocks, and we’re supposed to figure out how many rocks the other student collected, given that she collected 100 fewer rocks than the first student.
The words “fewer than” are special math words that give us a hint about what we need to do in order to get the right answer. Fewer than means the same as less than or a smaller number. We know that the second student has fewer rocks than the first, so that tells us that we need to subtract.
How many rocks does the first student have? 489.
How many fewer rocks does the second student have? 100 (shown in purple).
What does the word “fewer” tell us to do? Subtract (shown in red).
The first step to getting the right answer is to look for the special words that tell you what to do—fewer than means you probably need to subtract—in order to solve the question. The other very important part is to do the math very carefully. Don’t write 10 or 110 down instead of the correct number (100) when doing the subtraction.
How to solve word problems in general
A word problem is like a little story about a math question. The first step in solving the question is to read the story very carefully. You need to look for the special word or words that give you hints about what to do in order to get the right answer. Here are some examples:
- Adding words: more than, bigger than, taller than, greater than
- Subtracting words: fewer than, smaller than, shorter than, less than
The second step to take in solving the question is to look for the numbers in the story and then to do the correct math operation: adding or subtracting.
The last step is to check your work.
If you would like additional problems to help you master this skill, go to our online card catalog at VoxLearn.org, select one of the math collections, and enter the search terms “word problems grade 2”.